Successful Abdominal Aortic Aneurysm Research Articles

In Situ Repair of a Secondary Aortoappendiceal Fistula with a Rifampin-Bonded Dacron Graft

Secondary aortoenteric fistulas remain challenging diagnostic and therapeutic problems. Although the duodenum is most frequently involved, other intestinal segments are possible sites for fistulization. We report here a case of graft-appendiceal fistula revealed by recurrent gastrointestinal bleeding 11 years after abdominal aortic aneurysm replacement. The preoperative diagnosis was not achieved by endoscopy or imaging assessment. Despite recommended principles of total graft excision and extraanatomic bypass, appendectomy and in situ rifampin-bonded graft reconstruction were performed because of the advanced age and poor arterial runoff. The postoperative course was uneventful and the patient remains well 17 months after operation.

Long-Term Survival after Elective Repair of Infrarenal Abdominal Aortic Aneurysm: Results of a Prospective Multicentric Study

During 1989, 28 centers of the Association for Academic Research in Vascular Surgery (AURC) reported all cases involving patients with infrarenal abdominal aortic aneurysm (AAA) who reached the operating room alive. In a total series of 1107 procedures, 834 were performed electively. During 1993 and 1994, an effort was made to contact and, if possible re-examine the 794 (95.2%) patients who survived these elective procedures in order to establish survival curves, determine the causes of late death, and ascertain the predictive value for long-term survival of 628 perioperative variables recorded in 1989. Survival curves were calculated using the actuarial and Kaplan-Meier methods and compared with those obtained from national statistical records in a control population matched for age and sex. Variables with potential predictive value for late death were selected by univariate statistical analysis using either the chi2 or student t-test. In the group of 794 (92.5%) patients who survived elective AAA repair in 1989, survival rates were 93.9 +/- 1.8% at 1 year, 89.5 +/- 3.2% at 2 years, 83.5 +/- 3.2% at 3 years, 77.6 +/- 3.9% at 4 years, and 66.9 +/- 10.6% at 5 years. These rates were significantly lower than those observed in the control population. The mean annual death rate from cardiovascular disease was 1.8%, which was higher than in the control population matched for age and sex. Analysis using the Cox proportional risk model showed that the following variables were significant, independent predictors of late death: diameter of aneurysm (p < 0.02), choice of surgical approach in function of general status (p < 0.02), left ventricular insufficiency (p < 0.02), age (p < 0.02), carotid artery occlusion (p < 0.03), use of a surgical approach other than lobotomy (p < 0.04), cardiac arrhythmia (p < 0.04), duration of aortic clamping (p < 0.05), ECG evidence of myocardial ischemia (p < 0.05), abnormality at the upper limit of the aneurysm (p < 0.05), and advanced renal insufficiency (p < 0.05). Life expectancy in patients that undergo successful AAA repair is lower than in the general population. Although death is often unrelated to AAA or the repair procedure, the incidence of morbidity due to cardiovascular disease is higher than in a control population matched for age and sex. These findings suggest that better management of concurrent cardiovascular disease during the perioperative period and long-term follow-up holds the key to improving life expectancy in patients undergoing AAA repair.

Changing Aneurysmal Morphology after Endovascular Grafting: Relation to Leakage or Persistent Perfusion

Purpose: To relate changing abdominal aortic aneurysm (AAA) morphology after endovascular grafting to the presence of leakage, collateral perfusion, and other factors. Methods: Thirty-five patients who underwent successful AAA endovascular grafting were evaluated. Self-expanding Z-stents and Dacron grafts were applied in bifurcated and aortomonoiliac systems. Postoperative diameter changes were calculated from repeated spiral computed tomographic scans, angiograms, and ultrasonic phase-locked echo-tracking scans during a median 6-month follow-up (interquartile range [IQR] 3 to 12). Results: At 12 months, the diameters of completely excluded aneurysms had decreased 6 mm (IQR 2 to 11; p = 0.006). The proximal graft-anchoring stents had dilated 2 mm (IQR 0.5 to 3.3; p = 0.01). The aortic diameters immediately below the renal arteries but above the stents had not changed. Endoleakage and collateral perfusion (n = 13) were each associated with preserved aneurysm size and a 12 times higher risk of aneurysm dilation. After the leakage or the collateral perfusion had been treated, the aneurysm size decreased. Aneurysms with extensive intraluminal thrombi presented a reduced risk of leakage or perfusion. Conclusions: The diameters of endovascularly excluded AAAs decrease, except in cases of leakage or perfusion. Careful follow-up of patients with aortic endografts is necessary.

Subsequent proximal aortic operations in 123 patients with previous infrarenal abdominal aortic aneurysm surgery

Previous studies have reported that 3% to 8% of patients who have had resection of an infrarenal abdominal aortic aneurysm will subsequently have development of a new aortic aneurysm proximal to the repair. The actual incidence, pathogenesis, and natural history of these aneurysms are unclear. The purpose of this study is to better characterize subsequent proximal aortic aneurysms and to evaluate the outcome of their operative repair. We retrospectively reviewed our recent experience with surgery for new proximal aortic aneurysms in 123 patients who had had a prior abdominal aortic aneurysmectomy. Seventy-two patients (58.5%) were admitted with chest or abdominal pain, six (4.9%) were admitted with ruptured aneurysms, and 41 (33.3%) were symptom free. Most subsequent aneurysms involved the thoracoabdominal aorta (n = 94; 76.4%); others involved the juxtarenal abdominal aorta, descending thoracic aorta, or transverse aortic arch. The new aneurysm was in continuity with the existing prosthetic graft in 101 cases (82.1%). Resection and graft replacement of the aneurysmal segment was performed on an emergency basis in patients with evidence of impending rupture and electively when aneurysmal diameter exceeded 5.5 cm. The average time interval between the two operations was 8.2 +/- 5.4 years. Mean aortic clamp and visceral ischemic times were 39.7 +/- 14.7 and 33.5 +/- 12.8 minutes, respectively. The in-hospital mortality rate was 12.2%. Complications included oliguric kidney failure in 11.4% and paraplegia in 4.1%. These results compare favorably with previous studies. On the basis of the significant prevalence of subsequent proximal aortic aneurysms and the high mortality rate associated with their rupture, we recommend resection of the entire infrarenal aorta during abdominal aortic aneurysm replacement, followed by long-term surveillance with biannual computed tomography or magnetic resonance imaging scanning of the chest and abdomen. Early diagnosis is facilitated by a high index of suspicion and allows surgical intervention to occur before life-threatening rupture. Both emergency and elective proximal aortic surgery in these patients can be performed with acceptable levels of morbidity and mortality.

Successful Abdominal Aortic Aneurysm Resection in Long-Term Survivors of Cardiac Transplantation

With the improvement of survival rates following cardiac transplantation, the probability of recipients developing extracardiac disease is increased. Three cases are reported of abdominal aortic aneurysm successfully operated on in cardiac allograft recipients 1 to 4 years after transplantation. Indications for transplantation were valvular, idiopathic and ischaemic cardiomyopathy. Post-transplant hypertension and hyperlipidaemia may have played a role in the rapid growth of the aneurysms. Cardiac function and the incidence of graft atherosclerosis were assessed before surgery by coronary angiography. All three patients were discharged from hospital. Abdominal aortic aneurysm resection may be a safe procedure in cardiac transplant patients. In view of the rapid increase in the size of the aneurysms in transplanted patients, careful screening should be performed during follow-up.

Successful abdominal aortic aneurysm resection in long-term survivors of cardiac transplantation

With the improvement of survival rates following cardiac transplantation, the probability of recipients developing extracardiac disease is increased. Three cases are reported of abdominal aortic aneurysm successfully operated on in cardiac allograft recipients 1 to 4 years after transplantation. Indications for transplantation were valvular, idiopathic and ischaemic cardiomyopathy. Post-transplant hypertension and hyperlipidaemia may have played a role in the rapid growth of the aneurysms. Cardiac function and the incidence of graft atherosclerosis were assessed before surgery by coronary angiography. All three patients were discharged from hospital. Abdominal aortic aneurysm resection may be a safe procedure in cardiac transplant patients. In view of the rapid increase in the size of the aneurysms in transplanted patients, careful screening should be performed during follow-up.

Clinical Experience with a Collagen-Impregnated Knitted Dacron Vascular Graft

This report describes our first clinical experience with collagen-impregnated Dacron grafts in the aortic position. Fifty-four consecutive patients (43 men and 11 women), average age 67.5 years (44-84), received 11 tube grafts and 23 bifurcated grafts for abdominal aortic aneurysm replacement, 17 bifurcated grafts for aortic occlusive disease, two grafts for aortic pseudoaneurysm, and one graft for thoracoabdominal aneurysm repair. No preclotting maneuvers were used and there was no blood leak from the fabric upon restoration of blood flow, in spite of the use of systemic heparin. The hospital transfusion rate averaged 1.2 units in patients with occlusive disease and 2.7 units in patients undergoing aneurysm resection, which were similar to the transfusion rate in patients receiving standard knitted grafts prior to this study. There were two postoperative deaths from a myocardial infarction and a cerebral hemorrhage and no perioperative thromboembolic events. During a follow-up averaging 41.5 months (26-59), there were two late graft limb thromboses secondary to outflow disease progression. One patient died of aspiration two months postoperatively. Four patients died secondary to cardiac disease in at 13 and 21 months with functioning grafts. The rest of the patients are alive with functioning grafts. We conclude that the collagen-impregnated Dacron graft obviates the need for preclotting maneuvers because of a zero functional porosity.

Tube graft replacement of abdominalaortic aneurysm

In the 16 year period ending December 1985, 332 patients underwent elective abdominal aortic aneurysm replacement. One hundred fifty-four (46 percent) of these patients had tube graft replacement of the aneurysm. Patients were selected for tube graft on the basis of physical, angiographic, and intraoperative examinations. There were 123 mean and 31 women, with a mean age of 68 years. Complete follow-up ranging from 1 to 168 months (mean 53 months) was obtained in 137 of the surviving patients (87 percent). Two patients required revision to a bifurcated graft; one for iliac stenosis and one for iliac thrombosis. No iliac aneurysms were seen and no other aortoiliac complications were evident. Five other patients required femoro-distal reconstruction for either occlusive disease (three patients) or aneurysmal disease (two patients) at the groin or below. Life table analysis showed a 5 year survival rate of 65 percent and a 7 year rate of 54 percent. Conclusions drawn from this study reconfirm that in carefully selected patients, tube graft replacement of abdominal aortic aneurysm is an enduring procedure with few complications developing due to progression of iliac occlusive or aneurysmal disease.

Management of graft infections following abdominal aortic aneurysm replacement

AbstractGraft infection following resection of an abdominal aortic aneurysm is a rare but highly lethal complication. It is most commonly associated with aortoenteric fistula or external contamination when graft limbs extend to the groin. Other sources are bowel or urinary tract entry, latent infection in the aneurysm wall, breaks in sterile technique, or bacteremia. Diagnosis should be suspected when a patient with an aortic graft develops unexplained fever, especially with back or abdominal pain, gastrointestinal bleeding of any kind, or metastatic infection to the limbs. Diagnosis is difficult to establish. Endoscopy to demonstrate erosion into the distal duodenum or to rule out other sources of bleeding was useful in all 6 patients in which it was employed. Positive arterial cultures distal to the graft, the finding of bilateral hydronephrosis, and demonstration of periaortic inflammation on gallium scan are highly suggestive. Aortography was helpful in 2 of 6 patients but was useless when negative. Barium contrast x‐ray studies were usually negative (90%) or confusing. Management requires excision of all infected graft material, usually the entire prosthesis. Restoration of limb circulation, usually with axillo femoral bypass, should be done in all patients except those with prior amputation or previous iliac artery or graft occlusion with adequate collaterals. A 35% patient survival rate was achieved in 20 patients with graft infection and aortoenteric fistula. However, when a correct diagnosis was made without delay and appropriate principles of management were instituted, 78% (7 of 9) patients survived and no amputations were required in the 5 patients with intact limbs. Prevention of postaneurysmectomy graft infection requires meticulous aseptic technique, effective graft coverage and separation from loops of bowel with viable tissue, and the use of prophylactic systemic and local antibiotics.